Computer systems are now displaying a greater variety of graphics, video and other forms of data concurrently. However, many computer systems do not have sufficient bandwidth resources to update and display all these types of data on a display at the same time.
Some computer systems solve this problem by merely preventing the user from requesting more data than can be handled. That is, a computer system will disallow such overloads in the first place by insuring that the peak demand caused by all sources cannot exceed the minimum resource available. For example, the user might be limited in the number of video windows that may be opened at any given time on a display. However, this solution does not allow the user to decide how many data sources to display in the trade off between the number of sources or windows and the video display quality. It does not also allow efficient use of the resources available as the demand is not always at peak and the supply is not always at the minimum.
Other systems have utilized various techniques to degrade each frame of data being displayed to lower the bandwidth requirements. For example, U.S. Pat. No. 4,703,439 avoids overloads by varying the resolution of a displayed image. However, such a technique requires a large amount of video processing to perform the lowered resolution in a visually pleasing manner.
Another known technique is to vary the frame rate of an incoming video source. For example, a 16 frame per second video source might be modified to an 8 frame per second source prior to transmission for display. However, as multiple video sources with different frame rates may be displayed on a screen at the same time, it may be difficult to determine or allocate which video source should have an adjusted frame rate. In addition, the overload may be a very temporary overload and the adjustment of frame rate may be unnecessary.